The present technology relates to a lens module, an image capturing device, and an electronic apparatus. In particular, the present technology relates to a lens module, which drives a lens by using a displacement element having a flat-plate shape changed by application of a voltage, and an image capturing device and an electronic apparatus using the lens module.
In recent years, as functions of portable electronic apparatuses such as mobile phones, personal computers (PC), or PDAs (Personal Digital Assistant) have remarkably increased, apparatuses, each of which is equipped with a lens module so as to thereby have an image capturing function, have become popular. In such a portable electronic apparatus, in order to realize autofocus of a camera module, it is necessary to reciprocate a lens in a subject direction along the optical axis.
In the past, there was a general method of shifting the lens in the lens module through a driving section such as a voice coil motor or a stepping motor. However, recently, in terms of compactness, apparatuses using a polymer actuator element as a driving section have been developed. The polymer actuator element is configured such that an ion-exchange resin film is interposed between, for example, a pair of electrodes. With such a configuration, an electric potential difference is caused between the pair of electrodes, and thus the ion-exchange resin film is displaced in a direction orthogonal to the film surface.
As the lens module using such a polymer actuator element, for example, there is a lens module having a configuration in which a guiding shaft is provided that supports a movable mirror frame holding a lens group so as to move it along the optical axis and the polymer actuator element is disposed at a position where the element overlaps with the movable mirror frame in the optical axis direction. With such a configuration, the movable mirror frame is moved by the deformation of the polymer actuator element in the optical axis direction (for example, refer to Japanese Unexamined Patent Application Publication No. 2006-293006).
Further, as another configuration, there is a lens module having a configuration in which one set of polymer actuator elements of which the bending directions are different from each other are combined and a lens is mounted on one end portion of the polymer actuator element (for example, refer to Japanese Unexamined Patent Application Publication No. 2006-172635).